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PROV-ISSUE-62 (about-prov-language): about provenance language [Conceptual Model]

From: Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>
Date: Fri, 29 Jul 2011 09:09:38 +0000
To: public-prov-wg@w3.org
Message-Id: <E1Qmj4c-0004Tt-F1@barney.w3.org>

PROV-ISSUE-62 (about-prov-language): about provenance language [Conceptual Model]


Raised by: Graham Klyne
On product: Conceptual Model

Introduction of "characterized entities" - if this is something that
really needs to be said, I think it needs to be clarified.  I spent
some time thinking about these two sentences, trying to work out if
they could ever be completely correct, or just not understanding what
they are intended to convey:

[[ Furthermore, this specification is concerned with characterized
entities, that is, entities and their situation in the world, as
perceived by their asserters.

In the rest of the document, we are concerned with the representation
of such entities; their situation in the world will be represented
using sets of attributes.  ]]

Why "characterized entities" as opposed to perceived entities"?
What's the important distinction here?

The only interpretation I've found that makes sense to me is that the
document is concerning itself with entities that are characterized by
the values of some bounded set of attributes.  But that
interpretation, if correct, is not obvious to me from the wording

"PIL is a language by which representations of the world can be
expressed using terms that are drawn from a controlled vocabulary. "
I'm not sure how to interpret this.  Does this "controlled vocabulary
include, for example, numbers? Is this controlled vocabulary expected
to be the complete set of terms used in PIL expressions?

"These representations are relative to an asserter, and in that sense
constitute assertions about the world."  What is this trying to say?
I think you might mean something like:

"These representations are relative to the context of an asserter, and
in that sense constitute perceptions about the world."  which ties
back to the earlier statement about "as perceived by their asserters".

"All assertions in PIL SHOULD be interpreted as a record of what has
happened, as opposed to what may or will happen."  I feel we should
find a way to strengthen this SHOULD to a MUST, but comments from
earlier discussions make this tricky to get right.  Maybe:

"All assertions in PIL MUST be interpreted as a record of what has
happened or been observed in some context, as opposed to what might
happen or potential observations."  In this, I am using the reference
to a context to provide just enough wiggle-room for description in
future or imagined contexts.

"This specification does not prescribe the means by which assertions
are made, for example on the basis of observations, inferences, or any
other means."
The phrasing "... assertions are made" here is jarring, if not
confusing - I would think that assertions are made in PIL for the
purposes of this spec. Suggest "... how assertions are arrived at,

"The language introduces a notion of "provenance container", which
provides a default scope for assertions."  The term "container" here
is suggested of a physical or logical encapsulation, which I don't
think is meant.  How about "provenance context"?

[[ ... The model may define additional scoping rules for
assertions. Identifiers can safely be used within that
scope. Optionally, identifiers can be exported so that they can be
used outside their default scope. The language does not prescribe the
mechanisms by which identifiers are generated.  ]]

This spec is describing a data model, *not* a language.  It says so at
the top.  As such I think it's entirely inappropriate to start
defining linguistic constructs such as identifiers and scoping.
Assuming the actual language used will be RDF, I'm not seeing how what
you describe will be possible.

"In this specification, when an assertion is defined to refer to
another assertion about something, it does so by means of that thing's
identifier."  I don't understand what this is trying to say.
Received on Friday, 29 July 2011 09:09:43 UTC

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